In a presentation to Australian Opposition and cross bench parliamentarians on November 30, 2015, Patricia Ranald, coordinator of the Australian Fair Trade and Investment Network, suggested there are significant flaws in the arbitration system, including the potential for arbitrators to have a conflict of interest.

Leon Trakman, an arbitration expert, told Fact Check that "no system is perfect".

"However, institutions responsible for investor state arbitration, not limited to the International Centre for the Settlement of Investment Disputes (ICSID), have and are addressing concerns raised about it; and have not stood still in the face of legitimate criticism, " he said.

Professor Trakman points to a move to public hearings and the publication of written reasons for a decision, the ability of a party to seek judicial review of a decision and the growing endorsement of the International Bar Association's rules on conflict of interest.

On the issue of abiding by previous determinations, Professor Trakman said:

"While arbitration awards do not lead to judicial precedent, many national legal systems do not adhere to judicial precedent either. Instead, law develops through the opinio juris, the opinion of jurists. That is the way in which international investment law develops in significant measure, not unlike civil law across Europe, South America and parts of Asia. The same is the case in international law where institutions such as the appeal body of the World Trade Organisation does not subscribe to a strict system of precedent."